Japanese Patent Laid-Open No. 09-150137 is prior information concerning a method of discarding a unit containing toner.
To crush and pulverize a cartridge containing toner, a measure to counter a dust explosion caused by toner is necessary. One countermeasure is Japanese Patent Laid-Open No. 11-156224.
Also, Japanese Patent Laid-Open Nos. 05-301222 and 2000-159900 are inventions pertaining to the reuse of thermoplastic resins used in products such as copying machines, printers, facsimile apparatuses, and television sets.
Japanese Patent Laid-Open No. 2001-205245 is an invention related to a process of separating toner from a used process cartridge.
Furthermore, Japanese Patent Laid-Open No. 09-206685 is an invention concerning particle processing.
Image forming apparatuses, such as copying machines and laser beam printers, have rapidly spread with the progress of information communication technologies and the development of information communication apparatuses. Also, old apparatuses are extensively replaced with new ones as new products are developed.
In addition, old types of products are largely collected when they are replaced with new ones.
Methods of collecting and recycling household electric appliances, such as television sets and refrigerators, are established by the enforcement of the Household Electric Appliance Recycling Law. However, it is difficult to collect toner remaining in cartridges used in image forming apparatuses, particularly, printers and copying machines.
That is, to recycle cartridges, toner must be initially removed manually, and this increases the recycling cost.
On the other hand, if cartridges are crushed by a crusher without removing toner, the toner and some other particles scatter in a crushing vessel.
In addition, sparks generated when metal parts, such as agitating bars, developing blades, and sleeves, inside these cartridges are crushed by the crusher may function as ignition sources and induce a dust explosion.
Also, when cartridges are crushed and individual materials are selectively collected, toner strongly adheres to these materials.
Even if iron, aluminum, stainless steel, plastics, seals, and paper are separately removed and a specific material forming process cartridges is selected via several selecting steps, such as a screening step, a magnetic selection step, an air selection step, and a gravity selection step, after a crushing step, toner strongly adheres to the selected material. The adhered toner cannot be easily removed because the toner is charged and electrically sticks to the material.
If this recycled material to which the toner sticks is directly used as a molding material of a cartridge, the external appearance of the molded product declines, or the strength and/or the fire resistance of the molded material decreases.
As described above, a material which behaves as foreign matter with respect to a plastic material selected as a recycled material or a material which undesirably alters physical properties must be removed as much as possible.
It is possible to crush process cartridges in a crushing step and separate only plastic materials via a metal selecting means, such as one using magnetic selection, and a different material selecting means, such as one using gravity selection.
Furthermore, toner can be separated from plastic materials by introducing an apparatus using a cleaning device.
It is, however, difficult to select a specific plastic material from different types of plastic materials subjected to the cleaning step.